3.3 Statutory Deadlines, Extensions & Paid Preparer Due Diligence

Mastering statutory return deadlines, automatic extensions, civil compliance penalties, and professional due diligence requirements is essential for Enrolled Agents. The Internal Revenue Code imposes strict procedural timelines on taxpayers and demanding due diligence responsibilities on paid return preparers.

Statutory Deadlines and the Weekend/Holiday Rule

Under IRC §6072(a), individual income tax returns (Form 1040 and Form 1040-SR) filed on a calendar-year basis are due on the 15th day of the 4th month following the close of the tax year: April 15.

The Weekend and Legal Holiday Rule (IRC §7503): When April 15 falls on a Saturday, Sunday, or legal holiday, the due date advances to the next succeeding day that is not a Saturday, Sunday, or legal holiday.

• Emancipation Day (District of Columbia): Celebrated on April 16. If April 16 is a Saturday, it is observed on Friday, April 15 (moving the tax filing deadline to Monday, April 18). If April 16 is a Sunday, it is observed on Monday, April 17 (moving the tax filing deadline to Tuesday, April 18). Because IRS processing centers recognize DC holidays, Emancipation Day extends the federal tax deadline nationwide.
• Patriots' Day: Celebrated on the third Monday in April in Massachusetts and Maine. Taxpayers residing in Massachusetts and Maine receive an extra business day to file their returns.

For tax year 2025, April 15, 2026 falls on a Wednesday, making the unextended deadline Wednesday, April 15, 2026.

---

Automatic 6-Month Filing Extensions (Form 4868)

Taxpayers unable to file their return by April 15 can obtain an automatic 6-month extension of time to file by submitting Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return, on or before the original due date.

Key Principle: An Extension to FILE is NEVER an Extension to PAY!
- Form 4868 extends the filing deadline from April 15 to October 15.
- All taxes owed MUST be paid by April 15 to prevent statutory interest and penalties.

The 90% Safe Harbor to Avoid Failure-to-Pay Penalties: Under Treasury Regulation §301.6651-1(c)(3), a taxpayer who secures a valid Form 4868 extension will not be assessed the Failure-to-Pay penalty during the 6-month extension period if:

1. The taxpayer pays at least 90% of their actual total tax liability on or before the original April 15 deadline (through withholding, estimated payments, or payment accompanying Form 4868); and
2. The remaining balance of tax is paid in full when the return is filed (on or before October 15).

Important Limitation: The 90% safe harbor eliminates the Failure-to-Pay penalty, but it does NOT stop statutory interest. By law (IRC §6601), interest compounds daily on any unpaid tax from April 15 until the date of payment.

---

Special Statutory Extension Categories

1. U.S. Citizens and Resident Aliens Living Outside the U.S.

Taxpayers whose tax home and abode are outside the United States and Puerto Rico on April 15 receive an automatic 2-month extension to June 15 to file and pay without filing Form 4868. Taxpayers must attach a statement to their Form 1040 explaining their qualification. While the Failure-to-Pay penalty is waived until June 15, interest begins accruing on any unpaid tax on April 15. If additional time is required, they can file Form 4868 by June 15 to extend filing to October 15.

2. Military Service in Combat Zones (IRC §7508)

Military personnel serving in a designated combat zone (and civilian personnel in direct support) receive an automatic extension equal to: $\text{Extension Period} = 180\text{ days after leaving combat zone} + \text{Days remaining until April 15 when entering zone}$ This extension covers filing returns, paying taxes, filing refund claims, and IRS assessments. Crucially, no interest and no penalties accrue during this period.

3. Federally Declared Disaster Areas (IRC §7508A)

The IRS issues administrative notices extending filing and payment deadlines for taxpayers located within presidentially declared disaster areas. Both filing and payment penalties, as well as interest, are suspended through the announced extension date.

---

Civil Penalties for Late Filing and Late Payment (IRC §6651)

Enrolled Agents must guide clients who are unable to pay their tax liability. The overarching rule is: Always file on time, even if you cannot afford to pay.

First-Time Penalty Abatement (FTA): The IRS provides an administrative waiver for FTF or FTP penalties if the taxpayer has clean compliance for the preceding 3 tax years, has filed all required returns, and has paid or arranged to pay any outstanding tax.

---

Paid Preparer Due Diligence (IRC §6695(g) & Form 8867)

Congress enacted IRC §6695(g) to combat fraud and errors in refundable family tax credits and filing status claims. Paid tax return preparers who prepare returns claiming any of the following four covered tax benefits must satisfy rigorous due diligence standards:

1. Earned Income Tax Credit (EITC) (IRC §32)
2. Child Tax Credit (CTC) / Additional Child Tax Credit (ACTC) / Credit for Other Dependents (ODC) (IRC §24)
3. American Opportunity Tax Credit (AOTC) (IRC §25A(i))
4. Head of Household (HoH) Filing Status (IRC §2(b))

The Four Mandatory Due Diligence Requirements

1. Requirement 1: Complete and Submit Form 8867 The preparer must complete Form 8867, Paid Preparer's Due Diligence Checklist, and electronically transmit it with the client's Form 1040 (or attach it to a paper return).

2. Requirement 2: Computation Worksheets The preparer must complete the appropriate credit calculation worksheets found in the Form 1040 instructions, publication instructions, or tax preparation software equivalents.

3. Requirement 3: Knowledge and Reasonable Inquiry The preparer cannot accept taxpayer information at face value if it appears incorrect, inconsistent, or incomplete:

• The preparer must make reasonable inquiries if a reasonable and prudent tax professional would question the information.
• The preparer must make contemporaneous documentation (written interview notes created at the time of the inquiry) recording the questions asked, the taxpayer's answers, and the documents reviewed.

1. Requirement 4: Document Retention (The 3-Year Rule) The preparer must keep copies of all required due diligence records for 3 years from the later of:

• The statutory due date of the return (without regard to extensions); or
• The actual date the return was filed.

Records That Must Be Kept:

• A copy of completed Form 8867
• Copies of all credit and status computation worksheets
• Contemporaneous interview notes detailing taxpayer questions and answers
• Copies of any documents provided by the taxpayer on which the preparer relied (e.g., school enrollment records, birth certificates, medical records, Form 1098-T for education credits, landlord lease agreements for HoH)

The Statutory Penalty (IRC §6695(g))

For tax year 2025 returns filed in 2026, the statutory penalty under IRC §6695(g) is $650 per failure (indexed for inflation from $635 for returns filed in 2025; Rev. Proc. 2025-32 raises it to $665 for returns filed in 2027).

Multi-Credit Stacking Rule: The penalty is assessed separately for each covered benefit on a return. If a return improperly claims Head of Household status, the EITC, and the Child Tax Credit without meeting due diligence, the IRS can assess three separate penalties on that single return: $\text{Total Penalty} = 3 \times \$650 = \$1,950$